The present invention relates to a miniature gas turbine engine and, more particularly, to a thermal management system therefor.
Miniature gas turbine or turbojet engines are often utilized in single usage applications such as reconnaissance drones, cruise missiles, decoy and other weapon applications, including air-launched and ground-launched weapon systems. The use of such an engine greatly extends the range of the weapon in comparison to the more conventional solid fuel rocket engine.
To achieve economically feasible extended range expendable propulsion sources for such applications, it is necessary that the miniature gas turbine engines be manufactured relatively inexpensively yet provide the highest degree of starting and operational reliability when launched from air or ground systems. One component that greatly affects mechanical performance and reliability are the high speed bearings which support the rotating turbine machine. Reliability and efficiency of the bearing system is a priority for a successful expendable turbine engine. Such reliability and efficiency of the bearing system may be compromised through inadequate distribution of bearing lubrication.
Current gas turbine bearing systems may employ a relatively complex closed circuit lubrication scheme which may be difficult to maintain during long term storage typical of expendable single use systems.